Platelets are useful in the treatment of various pathologic conditions such as, for example, wounds, platelet deficiencies (e.g., thrombocytopenia), various genetic or acquired abnormalities, and severe blood loss. However, despite their high demand, the availability of platelets has been limited, at least in part, by their short shelf-life and the inability of current methods to preserve normal platelet function after storage for relatively long periods of time. There is a need therefore to develop platelet compositions that have increased shelf-life.